In the field of electronic components, there have been known techniques of applying a coating of an insulating film to a substrate on which a conductor layer is formed. For example, in a known technique for a semiconductor device, a substrate on which an electrode pad is formed is coated with an insulating film (a protective film, or a passivation film) provided with an opening portion communicating with the electrode pad.
On a substrate of an electronic component, wiring may be formed as a conductor layer. In the case of coating such a substrate with an insulating film, the wiring may form a step on the substrate, and the step may result in such poor coat ability of the insulating film that an edge portion of the wiring may be exposed through the insulating film. In this case, a protecting effect produced by the insulating film may be reduced, which may lead to a decline in the reliability of the electronic component.
The following is a reference document.    [Document 1] Japanese Laid-open Patent Publication No. 06-349886.